The Iranian authorities remain fearful of the power of student movements. That's the conclusion of youth activists who point to the increasing pressures they face in their efforts to bring down the current regime.

Activists said more than 650 students have been arrested since the opposition staged sizeable street protests on February 14. That figure could not be independently confirmed, but activists say the arrests indicate that the regime remains wary.

Two students were reportedly killed by security forces on February 14 and many more were detained before being released.

That protest – the first mass opposition demonstration in Iran in over a year -- was followed by another day of rallies on February 20 in Tehran and other cities. In the course of those rallies, a third student, Hamed Nour-Mohammadi, was reportedly killed by security forces in the southwestern city of Shiraz.

Since then, students say, the arrests have continued.

'Arrest Will Go On'

Salman Sima, an Iranian student and opposition supporter, says students were being taken from universities and that's worrying, "because it could mean that waves of arrests will go on."

Another activist, Pouyan Mahmudian, says that since the younger generation established itself as a driving force behind antigovernment protests in the Arab world, "the authorities in Iran have become increasingly wary of student movements in the country."

"Students are the key part of Iran's Green opposition movement, both in staging street protests and other actions as a [political] movement," Mahmudian says. "The authorities are sensitive when it comes to the mood at universities, and they consider it a potential source of threats."

Opposition websites reported that during the February 20 protests, security forces fired tear gas to disperse protesters who were chanting "Death to the Dictator!"

But while Tehran's police chief admitted deploying special forces in the capital, Iranian authorities overall maintain that the situation in the city was "peaceful."

Authorities 'Hijack' The Protests

Whether the authorities have deliberately downplayed the scope of the protests is unclear. Student activists, however, have accused the authorities of "hijacking" the deaths of protesters for their own benefit.

According to activists, Nour-Mohammadi was killed by security forces as he was trying to escape their attacks. But Iran's state-run media quoted the head of Shiraz University, Mohammad Moazeni, as saying Nour-Mohammadi died in a car accident and that he hadn't taken part in the antigovernment rallies that day.

The atmosphere at Shiraz University reportedly remains tense since Nour-Mohammadi's death. Student activists are not allowed to enter the university or its dormitories, and students and families have been told to remain silent on the subject of Nour-Mohammadi's death.

Contrary accounts also followed the death of Sanee Zhaleh, an art student who was killed during the February 14 protests. Zhaleh's friends and fellow students insisted he was a Green Movement supporter, but authorities claimed Zhaleh was a member of the Basij militia killed by antigovernment protesters.

Iranian youth have been at the center of recent protests in the country. Many students and young activists were among the 70 people killed in the mass unrest that followed the disputed reelection of Mahmud Ahmadinejad in 2009.

Mahmudian says that about 50 students, including some young women, were jailed before opposition protests began again this month. He says they are being held in harsh conditions.

"The rights stipulated for prisoners, by law, are even more restrictive for [political prisoners]. They are subjected to abuse as a way to put pressure on them," Mahmudian says.

Opposition activists say many families of recently arrested students have no information about their children's whereabouts.

According to Sima, two young women -- Saeedeh Asgari and Farnaz Kamali -- were among dozens of students from Tehran's Azadi University taken to unknown locations by security forces earlier this week.